Glucocorticoid receptors (GRs) are members of a highly conserved family of ligand dependent transcription factors which following hormone binding undergo homologous down-regulation reducing the levels of receptor protein. This decline in human GR (hGR) is due in part to a decrease in protein receptor stability that may limit cellular responsiveness to ligand. To examine the role of the proteasome protein degradation pathway in steroid dependent hGR responsiveness, we utilized the proteasomal inhibitors MG-132, β-lactone, and epoxomicin. HeLa cells and COS cells were treated with proteasome inhibitors in the presence of the GR agonist dexamethasone (Dex), or were pretreated with proteasomal inhibitor and then Dex. Dexamethasone induced glucocorticoid responsive reporter activity significantly over untreated controls, whereas cells treated with proteasomal inhibitors and Dex together showed 2-3 fold increase in activity. Protein sequence analysis of the hGR protein identified several candidate protein degradation motifs including a PEST element. Mutagenesis of this element at lysine 419 was done and mutant K419A hGR failed to undergo ligand dependent downregulation. Mutant K419A hGR displayed 2-3 fold greater glucocorticoid responsive reporter activity in the presence of Dex than wild type hGR. These differences in transcriptional activity were not due to altered subcellular localization, since when the mutant K419A hGR was fused with the green fluorescent protein (GFP) it was found to move in and out of the nucleus similarly to wild type hGR. Together these results suggest that the proteasome and the identified PEST degradation motif limit steroid-dependent human glucocorticoid receptor signaling. Foure key termsglucocorticoid receptor; proteasome inhibitor; dexamethasone; PEST

Background. Limited data are available regarding outcomes in elderly head and neck cancer patients.This retrospective study was designed to characterize head and neck cancer in geriatric patients. Patients and Methods. This study included all patients in a large university-based tumor registry who were diagnosed with head and neck cancer from January 1, 1990, to December 31, 2005. Patients aged $70 years at the time of diagnosis were defined as older. Overall survival and progression-free survival were censored at 60 months. Survival differences were compared using the log-rank test. Hazard ratios were estimated using a Cox proportional hazards model, adjusting for potential confounders. Results. Of 1,598 patients identified, 1,166 patients were aged ,70 years (i.e., younger) and 281 patients were aged $70 years (older).When controlling for possible confounders, older

5577 Background: Limited data are available regarding outcomes in elderly head and neck cancer patients. This retrospective study was designed to characterize head and neck cancer in geriatric patients in the UNC Tumor Registry. Methods: Of 1,598 patients identified from the registry, 1,291 patients were <70 years old (young group, YG) and 307 patients were > 70 (elderly group, EG) at diagnosis. Both overall survival (OS), calculated from diagnosis to death or the last follow up, and relapse free survival (RFS) were censored at 60 months. Log-rank test was used to compare survival difference. Cox proportional hazard model was used to estimate hazard ratio, adjusting for potential confounding factors. All tests were performed in R 2.13.1. Results: EG patients were more likely to present at an early stage with 25% presenting at stage I and 37% presenting at stage IV compared to 17% and 51% respectively in YG. EG had a median OS of 35 months (95% CI: 28-41 months) compared to approximately 60 months in YG (p < 0.0001 log rank test). The median RFS for EG and YG are 25 (95% CI: 20-32 months) and 44 (95% CI: 38-52 months) months respectively (p < 0.0001 log rank test). When controlling for possible confounders, EG patients were nearly twice as likely to die (HR 1.94, 95% CI 1.635-2.302, p<0.0001) and 70% more likely to relapse in 5 years compared to YG (HR 1.704, 95% CI 1.449-2.004, p<0.05). The median life expectancy for elderly patients in our study was nearly 5 years for stage I/II and <2 years for stage III/IV. Conclusions: Poor OS and RFS in elderly patients compared to younger patients in this study indicate a need for further investigation considering comorbidities and aggressiveness of treatment. Significant differences in life expectancy in elderly patients with early versus late disease may help guide patients and clinicians in determining how aggressively to treat.